This invention relates generally to truck bed covers and more particularly to security or hard tonneau covers for pickups.
Various security and hard tonneau covers are commercially available. These hard covers serve the purpose of keeping the contents of the truck bed out of view, are generally weather tight and prevent unauthorized entry into the truck bed.
Most hard covers are pivotally mounted to the front of the truck bed and open clamshell-like to the rear. This is mechanically simple, however access to the front of the truck bed is severely restricted. Cargoes tend to shift forward in truck beds, hence items tend to migrate to the front of the tuck bed where they are least accessible. If the cargo extends above the sidewalls of the truck bed, the cover cannot be closed. Even with the cover open, having the front of the cover hinged to the front of the truck bed prohibits hauling large items such as home appliances or motorcycles. Driving with this type of cover in the open position obliterates the driver's rear view.
Another type of hard cover is marketed as the Silver Spring. Both sides of the cover open on folding legs; either or both sides can be open at a time. It has the advantage of good access to the entire truck bed and has proven popular with tradesmen who need to secure their tools while maintaining good access to the truck bed. Another advantage is that the truck can be driven with the cover in the open position to haul items which extend above the sides of the truck bed. A disadvantage is the tedious opening and closing procedure which involves folding two legs on each side and the insertion or removal of locking pins.
Another hard cover is described in U.S. Pat. No. 5,364,154 entitled "Liftable Rigid Truck Bed Cover". This hard cover opens on four legs operating as a parallelogram. From the closed position, the cover lifts upward and rearward along the arc of the pivoting legs. This achieves good access to the pickup bed without the tedium of opening and closing a Silver Spring. However, the geometry of the opening and closing mechanism requires four latch points to secure the cover in the closed position. To keep the cover in the open position, this cover utilizes a height establishing mechanism which locks pins into one of several holes. These mechanisms for locking the cover in the open and closed positions make it expensive to manufacture and more complex than other truck bed covers.
It is clear that there is a need for an improved security cover for pickup beds.